suite/tests/linux/sigaction.c

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/*
 * Tests for sigaction and sigprocmask.
 */
#include "tools.h"

#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <sys/types.h>
#include <unistd.h>
#include <sys/syscall.h>

#define SENTINEL 0x12345678UL

#ifdef MACOS
typedef int si_mask_t;
#else
typedef unsigned long si_mask_t;
#endif

#if !defined(MACOS) && !defined(X64)
typedef struct old_sigaction_t {
    void (*handler)(int, siginfo_t *, void *);
    si_mask_t sa_mask;
    unsigned long sa_flags;
    void (*sa_restorer)(void);
} old_sigaction_t;
#endif

static void
test_query(int sig)
{
    /* i#1984: test that the prior action is returned */
    int rc;
    struct sigaction first_act;
    struct sigaction new_act;
    struct sigaction old_act;
    memset((void *)&first_act, 0, sizeof(first_act));
    first_act.sa_sigaction = (void (*)(int, siginfo_t *, void *))SENTINEL;
    sigemptyset(&first_act.sa_mask);
    sigaddset(&first_act.sa_mask, SIGUSR1);
    sigaddset(&first_act.sa_mask, SIGUSR2);
    rc = sigaction(sig, &first_act, NULL);
    assert(rc == 0);

    /* Test with nothing. */
    rc = sigaction(sig, NULL, NULL);
    assert(rc == 0);

    /* Test without a new action. */
    memset((void *)&old_act, 0xff, sizeof(old_act));
    rc = sigaction(sig, NULL, &old_act);
    assert(rc == 0 && old_act.sa_sigaction == first_act.sa_sigaction &&
           /* The flags do not match due to SA_RESTORER. */
           /* The rest of mask is uninit stack values from the libc wrapper. */
           *(si_mask_t *)&old_act.sa_mask == *(si_mask_t *)&first_act.sa_mask);

    /* Test with a new action. */
    memset((void *)&old_act, 0xff, sizeof(old_act));
    memset((void *)&new_act, 0, sizeof(new_act));
    new_act.sa_sigaction = (void (*)(int, siginfo_t *, void *))SIG_IGN;
    sigemptyset(&new_act.sa_mask);
    rc = sigaction(sig, &new_act, &old_act);
    assert(rc == 0 && old_act.sa_sigaction == first_act.sa_sigaction &&
           /* The flags do not match due to SA_RESTORER. */
           /* The rest of mask is uninit stack values from the libc wrapper. */
           *(si_mask_t *)&old_act.sa_mask == *(si_mask_t *)&first_act.sa_mask);

    /* Test pattern from i#1984 issue and ensure no assert. */
    memset(&new_act, 0, sizeof(new_act));
    memset(&old_act, 0, sizeof(old_act));
    new_act.sa_sigaction = (void (*)(int, siginfo_t *, void *))SENTINEL;
    sigaction(SIGINT, &new_act, 0);
    sigaction(SIGINT, &new_act, &old_act);
    new_act.sa_handler = SIG_IGN;
    sigaction(SIGTSTP, &new_act, &old_act);
}

static void
set_sigaction_handler(int sig, void *action)
{
    int rc;
    struct sigaction act;
    memset((void *)&act, 0, sizeof(act));
    act.sa_sigaction = (void (*)(int, siginfo_t *, void *))action;
    /* Arm the signal. */
    rc = sigaction(sig, &act, NULL);
    assert(rc == 0);
}

static int
make_sigprocmask(int how, void *sigset, void *oldsigset, int size)
{
#if defined(MACOS)
    /* XXX: Couldn't get the raw syscall to work on Mac. */
    return sigprocmask(how, sigset, oldsigset);
#else
    return syscall(SYS_rt_sigprocmask, how, sigset, oldsigset, size);
#endif
}

static void
test_sigprocmask()
{
#if defined(MACOS)
    sigset_t new = 0xf00d, new2 = 0x1234, old, original;
    /* We explicitly add SIGBUS to the blocked set as it is one of the
     * signals that DR intercepts.
     */
    sigaddset(&new, SIGBUS);
#else
    uint64 new = 0xf00d | (1 << SIGBUS), new2 = 0x1234, old, original;
#endif
    void *fault_addr = (void *)0x123;
    void *read_only_addr = test_sigprocmask;

    /* Save original sigprocmask. Both return the current sigprocmask. */
    assert(make_sigprocmask(SIG_SETMASK, NULL, &original,
                            /*sizeof(kernel_sigset_t)*/ 8) == 0);
    assert(make_sigprocmask(~0, NULL, &original, 8) == 0);

#if 1 // TODO: Not sure how to adapt this to fixing i#5261.
    /* Success cases.
     * The following should come before other tests so that some
     * signals that DR intercepts are blocked, which would require
     * DR to fix the old sigset manually before returning to the user
     * in -no_intercept_all_signals.
     */
    assert(make_sigprocmask(~0, NULL, NULL, 8) == 0);
    assert(make_sigprocmask(SIG_SETMASK, &new, NULL, 8) == 0);
    assert(make_sigprocmask(~0, NULL, &old, 8) == 0);
    assert(new == old);
#endif // TODO

    /* EFAULT cases. */
    /* sigprocmask on MacOS does not fail when the old sigset is not
     * readable or not writeable.
     */
    int expected_result_bad_old_sigset = IF_MACOS_ELSE(0, -1);
    assert(make_sigprocmask(~0, NULL, fault_addr, 8) == expected_result_bad_old_sigset);
#if !defined(MACOS)
    assert(errno == EFAULT);
#endif
    assert(make_sigprocmask(SIG_BLOCK, fault_addr, NULL, 8) == -1);
    assert(errno == EFAULT);
    assert(make_sigprocmask(SIG_BLOCK, NULL, fault_addr, 8) ==
           expected_result_bad_old_sigset);
#if !defined(MACOS)
    assert(errno == EFAULT);
#endif
    /* Bad new sigmask EFAULT gets reported before bad 'how' EINVAL. */
    assert(make_sigprocmask(~0, fault_addr, NULL, 8) == -1);
    assert(errno == EFAULT);
    /* EFAULT due to unwritable address. */
    assert(make_sigprocmask(SIG_BLOCK, NULL, read_only_addr, 8) ==
           expected_result_bad_old_sigset);
#if !defined(MACOS)
    assert(errno == EFAULT);
#endif

    /* EINVAL cases. */
#if defined(MACOS)
    /* Size arg is ignored on MacOS. */
#else
    /* Bad size. */
    assert(make_sigprocmask(SIG_SETMASK, &new, NULL, 7) == -1);
    assert(errno == EINVAL);
    /* Bad size EINVAL gets reported before bad new sigmask EFAULT. */
    assert(make_sigprocmask(SIG_SETMASK, fault_addr, NULL, 7) == -1);
    assert(errno == EINVAL);

#endif
    /* Bad 'how' arg. */
    assert(make_sigprocmask(~0, &new, NULL, 8) == -1);
    assert(errno == EINVAL);
    assert(make_sigprocmask(SIG_SETMASK + 1, &new, NULL, 8) == -1);
    assert(errno == EINVAL);
    /* Bad 'how' EINVAL gets reported before bad old sigset EFAULT. */
    assert(make_sigprocmask(~0, &new, fault_addr, 8) == -1);
    assert(errno == EINVAL);

    /* EFAULT due to bad old sigset still sets the new mask. */
    assert(make_sigprocmask(SIG_SETMASK, &new, NULL, 8) == 0);
    assert(make_sigprocmask(SIG_SETMASK, &new2, fault_addr, 8) ==
           expected_result_bad_old_sigset);
#if !defined(MACOS)
    assert(errno == EFAULT);
#endif
    assert(make_sigprocmask(~0, NULL, &old, 8) == 0);
    assert(new2 == old);

    /* Restore original sigprocmask. */
    assert(make_sigprocmask(SIG_SETMASK, &original, NULL, 8) == 0);
}

#if !defined(MACOS) && !defined(X64)
static void
test_non_rt_sigaction(int sig)
{
    int rc;
    old_sigaction_t first_act;
    old_sigaction_t new_act;
    old_sigaction_t old_act;
    memset((void *)&first_act, 0, sizeof(first_act));
    first_act.handler = (void (*)(int, siginfo_t *, void *))SENTINEL;
    first_act.sa_mask |= (1 << SIGUSR1);
    first_act.sa_mask |= (1 << SIGUSR2);
    rc = dynamorio_syscall(SYS_sigaction, 3, sig, &first_act, NULL);
    assert(rc == 0);

    /* Test with nothing. */
    rc = dynamorio_syscall(SYS_sigaction, 3, sig, NULL, NULL);
    assert(rc == 0);

    /* Test passing NULL to non-rt sigaction, which is used on Android (i#1822) */
    memset((void *)&old_act, 0xff, sizeof(old_act));
    rc = dynamorio_syscall(SYS_sigaction, 3, sig, NULL, &old_act);
    assert(rc == 0 && old_act.handler == first_act.handler &&
           /* The flags do not match due to SA_RESTORER. */
           /* The rest of mask is uninit stack values from the libc wrapper. */
           *(si_mask_t *)&old_act.sa_mask == *(si_mask_t *)&first_act.sa_mask);

    /* Test with a new action. */
    memset((void *)&old_act, 0xff, sizeof(old_act));
    memset((void *)&new_act, 0, sizeof(new_act));
    new_act.handler = (void (*)(int, siginfo_t *, void *))SIG_IGN;
    rc = dynamorio_syscall(SYS_sigaction, 3, sig, &new_act, &old_act);
    assert(rc == 0 && old_act.handler == first_act.handler &&
           /* The flags do not match due to SA_RESTORER. */
           /* The rest of mask is uninit stack values from the libc wrapper. */
           *(si_mask_t *)&old_act.sa_mask == *(si_mask_t *)&first_act.sa_mask);

    /* Clear handler */
    memset((void *)&new_act, 0, sizeof(new_act));
    rc = dynamorio_syscall(SYS_sigaction, 3, sig, &new_act, NULL);
    assert(rc == 0);
}
#endif

int
main(int argc, char **argv)
{
    test_query(SIGTERM);
    test_sigprocmask();
#if !defined(MACOS) && !defined(X64)
    test_non_rt_sigaction(SIGPIPE);
#endif
    set_sigaction_handler(SIGTERM, (void *)SIG_IGN);
    print("Sending SIGTERM first time\n");
    kill(getpid(), SIGTERM);
    set_sigaction_handler(SIGTERM, (void *)SIG_DFL);
    print("Sending SIGTERM second time\n");
    kill(getpid(), SIGTERM);
    print("Should not be reached\n");
}